Compressor



June 5, 192 8. 1,672,148

B. B| cHoF COMPRESSOR Filed Oct. 21. 1927 INVeNT'QQ patented June 5,1928.

UNITED STATES PATENT OFFICE.

BERNI-IARD BISCI-IOF, OF WINTERTHUR, SWITZERLAND, ASSIGNOR TO SWISSLOCOMO- TIVE AND MACHINE WORKS, OF WINTERTHUR, SWITZERLAND, ACORPORATION OF SWITZERLAND.

COMPRESSOR.

Application filed October 21, 1927, Serial No. 227,823, and in GermanyNovember 1, 1926.

This invention relates to a compound arrangement for compressors of themultistage type.

In cell-compressors for high pressures, such as are necessary inrefrigerating inachines, compression must be effected in more than onestage. For this purpose two or more casings are mounted one behindanother on a base plate common to them all, and their shafts areconnected together by elastic couplings. The latter are necessarybecauite it is diiiicult to arrange the individual rotors exactlycoaXially. This necessitates however that each shaft extending out ofits casing shall be packed by a stuffing box. The more stuiiing-boXesare necessary, particularly in refrigerating machines, the more loss anddefects in working may occur, particularly when high gas pressures aredealt with.

This invention has for its main object to obviate this defect.

To this end, there is connected between each two casings situated onebehind another an intermediate member which encloses the elasticcoupling and shuts it oti from the atmosphere. If the intermediatemember is also to equalize inequalities in the erection of the twocasings, and to take care of varying expansion due to changes oftemperature,

its shape must admit of deformation within certain limits. The inventionenables two stages-of a compressor which are connected by such anintermediate member to be erected much more simply and at a lower costthan in any other manner.

Two embodiments of the invention are illustrated diagrammatically and byway of example in the accompanying drawings, wherein p Figure 1 is anelevation, partly in section, showing a rigid intermediaite memberbolted to two adjacent stages, and

Figure 2 is a like view showing an elastic intermediate member bolted totwo adjacent stages or cells.

Like reference numerals parts in both views.

Referring first to Figure 1, the intermediate member aforesaid is in theform of a cylin der 1 having at its ends flanges 5, 5 bolted to thestages or cells 6 and 7 to be connected.

designate like Any gas that escapes through stufiing-boxes provided inthe end covers 2, 2 will collect in the cylindrical intermediate member1 and are led through a tubular branch connection 3 to the inlet of thelow pressure stage 6. An elastic coupling is provided within thecylinder 1 between the shafts of the rotors of stage 6 and stage 7.

Figure 2- shows a tubular intermediate member 4- bolted by flanges 5 tothe end cover plates 2 of the stages 6 and 7. The shape, material andwall-thickness of this member 4 are so selected that the memberparticularly can accommodate expansion due to heat. In this constructionalso it is preferable to lead gas that leaks from the two stages 6, 7through the stuiiing-boxes, to the suction pipe of the low pressurestage of the compressor by way of a branch pipe 3 that opens into thetubular intermediate memher 4.

I claim 1. In a multi-stage compressor, the combination with two casingsconstituting each a stage arranged end to end and having each a rotor,and a coupling connecting the rotors, of an intermediate memberenclosing from the atmosphere the space between the ends of the casingscontaining said coupling.

2. In a multi-stage compressor, the com bination with two stagesoperatively connected end to end, of a tubular intermediate member whichshuts off from the atmosphere the space between the adjacent ends of thestages.

3. In a multi-stage compressor, the combination with two stagesoperatively connected together end to end, of an elastic tubularintermediate member which is connected air-tight to said stages andshuts off from the atmosphere the space between the adjacent ends of thesaid stages.

4. In a compressor of the character described, the combination with twocells operatively connected together end to end, of an intermediatemember that is connected air-tight to said cells and shuts off from theatmosphere the space between the adjacent ends of said cells, whichintermediate member has an aperture for connection with the suction sideof the low-pressure cell.

In testimony whereof I aflix my signature.

BERNHARD BISCHOF.

